.nw { background: url(rounded_nw.gif) left top no-repeat }
.ne { background: url(rounded_ne.gif) right top no-repeat }
.sw { background: url(rounded_sw.gif) left bottom no-repeat }
.se { background: url(rounded_se.gif) right bottom no-repeat }

.n { background: url(rounded_n.gif) top repeat-x }
.s { background: url(rounded_s.gif) bottom repeat-x }
.e { background: url(rounded_e.gif) right repeat-y }
.w { background: url(rounded_w.gif) left repeat-y }